Apparatus for and method of breaking coal



Aug.A 13, 1940. a. J. MEYER 2,211,243

y APPARATUS FOR `AND METHOD QF BREAKING COAL I Filed Jan. 24, 1938 INVENTOR. RALPH JMfyf/P @fc5/w50 .2W .fao/rb' L MEYER, wif/wsrRAr/f/,r

vmoRNEY.

Patented Aug. 13, 1940 UNITED y STATES annals APPARATUS FOR AND METHOD F BREAKING COAL Ralph J. Meyer, deceased, late of Denver, Colo., by Judith L. Meyer, administratrixDenver,

Colo.

Application Januaryv 24, 193s, serial No. 186,621

Claims.

.This invention relates to a method and apparatus for breaking coal in natural formations through the intermediary of an expansivevfluid.

Methods heretofore employed consist of placing an expansible element in a bore of the coal Vein and then introducing an expanding pressure uid 'into the element whereby to exert a breaking force on the'coal formation. Methods of this character are exemplied in United States Patents No. 1,879,907 and No. 1,915,687, issued to the inventor of the present method. y

It has been found that the methods described in the above mentioned patents were effective only under favorable conditions but did not always produce the desired results.

Therefore, it is an object of the present invention to provide a simple method and apparatus by which the coal in the area adjacent the eX- pansible element is subjected to sudden shocks rather than to a gradually applied and progressively increasing pressure.

A further object of the invention is to combine the old method and the new method by first employing a breaking force steadily, to be followed by suddenly applied impulses of increased pressure.

Anothero-bject of the invention is to provide, for the purpose above mentioned, an yapparatus oi simple and efficient construction under full control of the operator; and still other objects and advantages will be found in the course of the following description made with reference to the accompanying drawing. In the drawing, in the several views of which like parts are similarly designated.

Figure 1 is a partly diagrammatic view, illustrating means that are well adapted to carry out the improved method;

Figure 2 is a longitudinal section of part of the device shown in Figure 1;

Figure 3 is a sectional view, of part of the apparatus shown in Figure 1, and drawn to a larger scale; and

Figure 4 is a sectional View on line II- of Figure 2.

In the drawing, reference character I2, denotes a power unit, such as an electric motor, that is in driving connection with a pump I3, having an intake conduit I4 and a discharge conduit I5. A tank or other form of reservoir, is shown at I Ii, having a dividing partition I'I, through which is a cone valve I8, operated by a handle I9, extending exteriorly of the tank.

The lower division of the tank is provided with a liquid sight-gauge 20. The discharge conduit I5 is provided with a check valve 2 I, and a threeway valve 22, through which it leads to a flexible conduit 23, that connects with a eXible and laterally expansible tube or capsule 24, that is shown operatively positioned in a drilled hole 25 in a coal vein 2B.

The three-way valve 22 may be manually, or otherwise, rotated to direct the output from the pump, through a branch conduit 21 into an accumulator 28, that comprises a cylinder 29, a piston 30 therein, with a packing gland 3l, and a piston rod 32 therethrough, on which is a cross head 33, that bears against compression springs 34.

An outlet conduit 35, leads from the accumulator back to the main discharge conduit I5, and is provided with a pressure-indicating gauge 35 and a shut-01T release valve 3l.

1n Figures 2 and 4, the details of the expansible tube element, 24, are more fully illustrated and they comprise a thick-walled eXible and eX- pansible tube 38, that is capped at each' end with a closing element, or cap 39, each of which has an inwardly projecting nipple, 39a, that engages the inner surface of the tube 33, which is securely clamped therearound, by bands 50, each having a rounded edge lilla, positioned inwardly of the assembly, to prevent cutting or other damage to the tube, when expanded.

The two caps are connected by a hollow rod 4I, having apertures 42 in communication with the closed interior of the tube. A pipe nipple 43 serves to complete the connection between the flexible conduit 23 and the hollow rod, while the latter serves the useful purpose of tying the end caps together to prevent longitudinal expansion of the flexible tube 38.

The expansible element, 24, is an improvement over the similar devices disclosed in Meyer Patents Nos. 1,879,907 and 1,915,687, and these improvements are being claimed in another application, Serial No. 189,127, thepresent application being devoted, primarily, to the method of coal breaking.

The improved method for breaking coal is as V45 follows: A substantially non-compressible liquid is placed in the upper division of the tank I6, and a predetermined and measured amount thereof, is permitted to flow to the lower division of the tank, by means of the cone valve I8, wherefrom it is pumped into the system above described. The operator first permits the pumped liquid to be delivered directly through conduit I5 into the expansible tube element 2e, to start the cracking of the coal by the hydrostatic pressure applied to the inner walls oi the drilled hole 25, in the coal vein.

After fracture has begun, the three-way valve s is rotated to close conduit l5 and direct the pumped liquid into the accumulator 28, which drives the piston thereof, downwardly, compressing the springs 36.1, until a predetermined pressure is indicated on the gauge 36, whereupon the operator opens the release Valve 3'1, to release the stored or accumulated pressure, thereby delivering a shock or water-hammer blow to the breaking coal through the conduits l5 and 23 and the walls of the expansible tube 38.

A three-way valve of this character permits closing of the passage to the accumulator and direct movement of fluid to the tube 38, or the closing of the direct passage to the tube 38 and discharge of the pump into the accumulator, or closing of the pump discharge passage, and opening communication between the accumulator and the tube through passage 21, or if desired, simultaneous closing of the passage l5 and the branch 27.

The sudden shock to the previously cracked and breaking coal, has been found to be more effective than a continuing steady internal pressure, and this method prevents the expansible tube from being damaged, by preventing it from being slowly forced into the cracks as they open in the coal, adjacent the drilled hole 25, which would occur if steady pressure were continued as begun.

Obviously, the elements of the accumulator could be reversed, or some other type of accumulator could be substituted for the one that is shown, merely as an example. The piston 3Q, for instance, could be forced outwardly against tension springs. In the arrangement shown, the lower end of the cylinder could be provided with a small closable common air valve and, if closed, the air on the side of the piston that is opposite to the pressure liquid, can be used as an elastic compressive cushion to aid the compression springs 24, in their function,

A plurality of branch conduits may be used to serve a plurality of expansible tubes, simultaneously, and the apparatus may preferably be mounted for easy transportation, as, for instance, on a mine car or the like.

By virtue of providing a measured amount of liquid for the pump, only a limited pressure can be built up in the system. As a further safeguard, if, for any reason, pressure, in the system, exceeds a predetermined point, a pressure relief valve fill, will automatically open to pass liquid back into the tank I6, via conduit 45. A manually operable valve 46, may also be opened, when desired, to return liquid to the tank.

The full equivalent of the release valve 3l, may be arranged for, either manual or automatic opening at a predetermined pressure, or time, and/or for repeated openings at intervals, the preferred object being to follow steady disruptive preliminary pressure, with one or more shocks or blows to the coal, or a series of shocks may, in some instances, suice without preliminary pressure.

Thus, coal may be broken from the vein safely,

economically and e'iciently, with a high percentage of large lumps and with no delays required to clear the mine of smoke or gas, and with no damage to the expansible tubes, other than normal wear.

Steady expansive breaking pressure has been applied in drilled holes in coal veins heretofore, but the present improvement resides, primarily, in following this with a shock or a series of shocks, radially in all directions or in substituting a shock or a series of shocks, for the steady pressure.

What is claimed and desired to be secured by Letters Patent is:

1. The method of breaking coal or the like in natural formations, which comprises i'lrst subjecting coal within such a formation to a sustained uid pressure, establishing a iuid body under higher pressure, and applying said higher pressure to the coal body under the sustained pressure, by a sudden release of the established iiuid body into an expansible element within the formation.

2. They method of breaking coal which comprises, measuring a quantity of liquid, pumping some of the liquid into an expansible element within a body of coal thereby subjecting said coal to pressure, accumulating some of the liquid under pressure exteriorly of the said element, and then admitting the force of the accumulated liquid to the expansible element.

3. In a method of breaking coal or the like inclusive of a dow of fluid under pressure and the step of applying the expansive force of said iiuid while confining it, the improvement which comprises diverting some of the fluid to accumulate the same under pressure, and suddenly releasing the pressure of the accumulated fluid into the expanding and confining means, providing a forcey impulse superimposed on the expanding force.

4. In apparatus for breaking coal or the like inclusive of an expansible element and a source of fluid-dow under pressure connected with said element, the improvement which comprises an accumulator connected with the source of fluidiiow and connected with the expansible element, means for optionally directing the fluid-flow to said element or to the accumulator, and means for suddenly releasing the force of the fluid in the accumulator into the eXpansible element.

5. In apparatus for breaking coal or the like inclusive of an expansible element and a source of fluid-flow under pressure connected with said element, the improvement which comprises an accumulator connected with the source of fluidiiow and connected with the expansible element, means for optionally directing the fluid-now to said element or to the accumulator, means for automatically returning the uid-iiow to the source when a predetermined pressure has been built up in the accumulator, and means for suddenly releasing the force of the uid in the accumulator into the expansible element.

JUDITH L. MEYER. Administrati of' the Estate of Ralph J. Meyer,

Deceased. 

